Magnet vehicle

ABSTRACT

A magnet vehicle supportedly adhered to and adapted to run over an inclined wall surface of a structural member made of a strong magnetic material such as iron and steel, characterized in that said vehicle can be altered of its direction of travel as desired on said surface.

United. States Patent [1 1 Hiraoka et al.

[ 1 Dec. 11, 1973 MAGNET VEHICLE Inventors: Michito Hiraoka, Ageo;Yoshihiko Hikita, Fukaya, both of Japan Assignee: Hitachi Metals, Ltd.,Tokyo, Japan Filed: Feb. 10, 1972 Appl. No.: 225,195

Related U.S. Application Data Division of Ser. No. 36,753, May 13, 1970,Pat. No. 3,682,265.

Foreign Application Priority Data May 16, 1969 Japan ..44/37383 Aug. 1,1969 Japan ..44/604l0 U.S. Cl 180/9.44, 114/222, 335/296,

180/1 VS Int. Cl B62d 11/00, B62d 55/00 Field of Search l80/9.44, 9.48,9.38,

180/1 VS, 9.2 R; 114/222; 335/229, 296

[56] References Cited UNITED STATES PATENTS 3,682,265 8/1972 Hiraoka etal. 180/92 2,132,661 10/1938 Temple 114/222 X Primary ExaminerKenneth H.Betts Assistant Examiner-John A. Pekar Att0rney-Paul M. Craig et al.

[57] ABSTRACT 2 Claims, 8 Drawing Figures "MENIEUUEc n 1915 SHEET 3 BF 4MAGNET VEHICLE This is a divisional application of copending U.S.application Ser. No. 36,753, filed May 13, l970, now US. Pat. No.3,682,265. I

The present invention relates to a steered magnet vehicle supportedlyadhered to a vertical or inclined wall surface of a structural membermade of a magnetic material such as iron and steel and adapted to travelover said surface for various operations such as painting, inspection ofwelded portions and so on, various devices for such purposes beingmounted thereon.

Heretofore, it has been necessary to construct platform for operatorsby, for example, combining wooden bars or rods, or otherwise to suspendgondola or cradle or the like from above, when painting or inspectingships or large buildings. Thus, the operators had to work by hand onsuch platform or in such gondola located at a considerable height. Forthis reason, the operation was dangerous and, in addition to this, theefficiency of operation was extremely low.

To overcome the above disadvantages, various steered magnet vehicleshave been proposed. However, such magnet vehicles heretofore proposedhave proved to be not-satisfactory, for example, in that, when themagnet vehicle is driven over a surface having a certain curvatureinstead of a flat plane of a structural member, it was not possible toobtain a sufficient adhesion force for supporting its weight and furtherthat it tended to sometimes damage the operation surface due to thecontact pressure exerted between the vehicle and the operation surface.Thus, any satisfactory magnet vehicle has not been put to a practicaluse.

In case of steered magnet vehicles heretofore proposed, they are adheredto an operation surface by permanent magnet means and/or electromagnetmeans mounted thereon, and driven by driving or magnetic belts providedon both sides of the vehicle, which belts being driven by electricmotors. In case of changing the direction of travel of the magnetvehicle of this type, it was done by driving only the belts located onone side of the vehicle, while the other belts located on the oppositeside being stopped or reversely driven, whereby turning the magnetvehicle in a certain radius of turn. However, when the vehicle issupported on an almost vertical wall surface, it had the tendency ofslipping at the contact area either of the right or left belts duringthe turn of the vehicle owing to the change in the contact pressurebetween the vehicle and the wall surface. Accordingly, remarkable skillwas required to turn the magnet vehicle exactly in the desireddirection, and it required a relatively large radius of turn and a longtime to accomplish turning of the vehicle.

It is therefore an object of the present invention to provide a steeredmagnet vehicle which can alter its direction of travel with highreliability, with ease, in a remarkably short while in comparison withthe conventional ones and even in a considerably restricted area.

In accordance with the present invention, there is provided a steeredmagnet vehicle comprising central magnet means, lateral magnet means,the gap between the lower end of the electromagnet means and anoperation surface being adjusted in accordance with the curvature ofsaid operation surface in order to maintain a predetermined adhesionforce therebetween, driving endless belt means adapted to be driven bydriving pulley means, take-up pulley means and guide pulley meansmounted on frame members, planetary gear means associating with a gearfixedly secured to said central magnet means for altering the directionof travel of the magnet vehicle.

In accordance with another embodiment, the invention is a steeredmagnetic vehicle comprising central magnet means mounted on an upperframe and including means for automatically adjusting the verticalmovement of the central magnet means in order to maintain a constantadhesion force between the vehicle and the surfaces upon which it rides,a pair of endless track means disposed on opposite sides of said framefor frictional driving of the vehicle, lateral magnet means disposedbetween the upper and lower runs of said track means, and a pair ofmotor means each adapted to drive a different one of said track means toenable steering thereof.

Other objects, features and advantages of the present invention willbecome apparent to those skilled in the art' from the following detaileddescription and attached drawings on which, by way of example, only thepreferred embodiments of the present invention are illustrated, inwhich:

FIG. 1 is a plan view illustrating one embodiment of the steered magnetvehicle according to the present invention.

FIG. 2 is a side view of the vehicle shown in FIG. 1.

FIG. 3 is an enlarged view in section on the line III- -III shown inFIG. 1.

F IG.'4 is a longitudinal, sectional view illustrating lateral magnetmeans in detail.

FIG. 5 is a plan view illustrating another embodiment of the magnetvehicle according to the present invention.

FIG. 6 is a side view illustrating the magnet vehicle of FIG. 5 in itsvertical section.

FIGS. 7 and 8 are sectional views illustrating in detail a steeringmeans incorporated in the magnet vehicle shown in FIG. 5.

One preferred embodiment of the present invention will now be describedhereinunder merely by way of example with reference to FIGS. 1 through4. In this specification it is contemplated that dashed referencenumeral means members disposed at the right-hand side with respect tothe longitudinal center line of the vehicle.

l and 1 and 2 and 2' are driving endless V-belts which are wound arounddrive pulleys 3 and 3', take-up pulleys 4 and 4, guide pulleys 5 and 5and small pulleys 6 and 6' and adhered to the side wall or the undersurface of the structural body 38 made of iron or steel and serve todrive the magnet vehicle. The aforementioned driving endless V-belts aredriven through rotation of the driving pulleys 3 and 3'. 7 is a supportmember for said driving pulleys of non-magnetic material. The drivingpulleys supported in said support member 7 by means of bearings 8 and 8'are associated with driving motors 9 and 9' in said driving pulleysupport member 7 via couplings l0 and 10', and they are drivenindependently by means of said driving motors 9 and 9'.

The driving motors 9 and 9' are operated by remote control means and arepreferably of the electric or pneumatic type for the purpose ofdecreasing the weight of the vehicle. 11 and 11' are side wall memberssymmetrical with respect to the longitudinal axis of the vehicle, andcomprise respectively lateral magnet means 13 and 13' and three pairs ofguide pulley means 14 and 14.

The lateral magnet means 13 and 13 consist respectively of frames 12 and12 of non-magnetic material, permanent magnets 15 and 15', upper heelpieces 17 and 17' and lower heel pieces 18 and 18. Guide grooves 19 and19' are provided for receiving the driving belts 1 and 1' and 2 and 2 onthe upper surface of the frames 12 and 12 and on the lower surface ofthe lower heel pieces 18 and 18', respectively.

The guide pulley means 14 and 14' are provided in the frames 12 and 12'in three pairs on the right and left of the vehicle, and comprise guidepulleys 5 and 5', support frames 20 and 20' for said guide pulleys,bolts 21 and 21' for suspending the support frames 20 and 20 from theframes 12 and 12' and springs 23 and 23' provided between said frames 12and 12 and said support frames 20 and 20' and disposed around the bolts21 and 21' and nuts 22 and 22'.

24 is a central magnet means which is comprised of upper frame 25, worm26, worm wheel 27, cover 28 for these members, shaft 30 including ascrew 29 adapted to be vertically displaced through the rotation of saidworm wheel 27 and magnet 31 fused to the lower end of said shaft 30. 32is a coil, which is mounted within a yoke 34 by means of a shaft 33. 35is a reduction and lift motor which is associated with the worm 26 viathe coupling 36. 'A limit switch 37 is attached to the yoke 34cooperating with the reduction and lift motor 35 so that the distancebetween the electromagnet 31 and the structural member 28 of iron orsteel may be maintained constant. There are provided on the lateralframes 12 and 12', a plurality of guide rollers 39 and 39, respectively,so that the electromagnet 31 may be vertically moved along a suitablegroove formed in the yoke 34 when it is moved upward or downward.

40 is a support frame of non-magnetic material for supporting thetake-up pulleys 4 and 4' and the small pulleys 6 and 6' .Take-up pulleys4 and 4 are mounted thereon in the manner that their location may beadjusted with ease. 41 is a painting nozzle mounted on the upper frame25.

Said frame pulley support frame 7, lateral frames 12 and 12', upperframes 25 and support frame 40 are respectively interconnected with eachother by suitable means such as bolts and nuts, and they constitute themagnet vehicle together with the aforementioned various elements andmeans.

In the above arrangement, when the magnet vehicle is placed upon a sidewall or under surface of the structural member 38 by means of suitablemeans such as a crane, the lateral magnet means 12 and 13' adhere to thesurface of the structural member 38 via the driving V-belt 1 and 1 and 2and 2' guided by the grooves 19 and 19' formed in the upper surface ofthe frames 12 and 12' and the lower heel pieces 18 and 18'.Subsequently, when the electromagnet 31 is activated by the limit switch37 in association with the mechanism comprising the reduction and liftmotor 35, coupling 36, worm 26, worm wheel 27, screw 29 and shaft 30,the magnet vehicle then adheres to and is firmly supported on a sidewall or under surface of the structural member 38.

After the vehicle adheres to and is supported on the structural member,it is operated by means of remote control means (not shown) mounted onthe vehicle and a control board (not shown) provided on or away from thestructural member 38. When it is required to advance the vehiclestraight, the two driving motors 9 and 9' are rotated at the same speed,whereupon the driving pulleys 3 and 3 are rotated intermediary of therespective couplings 10 and 10 to advance the driving V belts 1 and 1'and 2 and 2'. When it is required to change the direction of advance,only one of said two driving motors 9 and 9' is driven.

During the movement of the vehicle, the entire weight of the vehicle andvarious devices mounted thereon are supported by either of or both ofthe central magnet means 24 and the lateral magnet means 13 and 13'. Itis preferable that the gap between the respective heel pieces 18 and 18'of the lateral magnet means 13 and 13' and the surface of the structuralmember 38 be in the magnitude of about l-3 mm. Such magnitude of gap isachieved by the driving V-belts l and 1 and 2 and 2 fitted in thegrooves 19 and 19' formed in the heel pieces 18 and 18. The springs 23-and 23' of the guide pulley means 14 and 14 act in accordance with the,curvature of the structural member 38 so that said gap between the lowersurface of the heel pieces 18 and 18 and the surface of the structuralmember 38 may be maintained constant.

In case of the central magnet means 24 on the other hand, it is alsopreferable to maintain the gap between the electromagnet 31 and thestructural member 38 at a predetermined optimal value. For this purpose,there are provided on the lateral wall of the electromagnet 31 aplurality of limit switches 37 for normally or reversely rotating thereduction and lift motor 35 and thereby displacing the electromagnet 31upwardly or downwardly. Thus, the gap between the electromagnet 31 andthe structural member 38 can be automatically adjusted at a given,constant value, in spite of the fact that the curvature of thestructural member 38 varies along the pass of the vehicle. The magnetvehicle can be removed with ease from the surface of the structuralmember 38 by simply supporting the magnet vehicle by suitable means suchas a crane, or otherwise by switching off the limit switches 37 to theirnon-operable positions and abutting the yoke 34 of the electromagnet 31to the structural member 38 and thereby cutting off the electric currentand removing the magnetic force exerted by the lateral magnet means 13and 13' to the structural member 38.

Another preferred embodiment of the present invention will now bedescribed below with reference to FIGS. 5 through 8. In the drawings,101 is an electromagnet, 102 is a coil for said electromagnet 101, and103 is a central frame for interlocking and supporting various elementsof the vehicle. 104 and 104 are driving wheels while 105 and 105 aredriven wheels. 106 and 106 are lateral frames. 107 is an air cylindermeans for vertically moving the electromagnet 101, and comprises an aircylinder 108 secured to the frame 103, a piston 109 adapted to beslidingly moved within said cylinder 108 and a rod 110 fixed to saidpiston 109 at one end and to said electromagnet 101 at its opposite 1end. 111 and 112 are inlet and exhaust ports of compressed air used forvertically moving the piston 109, and connected to a pipe respectively.113 is a bearing in which the rod 110 is slidingly moved. 114 is thelower end portion of the heel piece of the electromagnet 101. 1 15 is asteering means and it comprises a driving motor 116, bevel gears 117 and118, a shaft 119 having the bevel gear 118 secured at one end, a spurgear 120 secured at the other end of said shaft 119 and large gear 121to be engaged with said spur gear 120 and fixedly mounted on theelectromagnet 101. 122 is a bearing for the shaft 1 19 provided in thein the center frame 103, and 123 is a guide bore for said shaft 119provided in a bracket 124. 125 and 125' are driving belts wound aroundthe driving wheels 104 and 104' and the driven wheel 105 and 105. 126and 126' are driving motors mounted on a support frame 127 provided inthe center frame 103, which motors are arranged to drive the drivingwheels 104 and 104', respectively, and thus, via driving belts 125 and125', the magnet vehicle is driven. 128 is a gap existing between thesurface 129 of a structural member made of iron or steel and theadhesion end 114.

In the arrangement of the present invention, the force for adhering themagnet vehicle tothe surface of the structural member is exerted by theelectromagnet 101 and permanent magnet means incorporated in the lateralframe 106 and 106'. In case that the total weight of the magnet vehicleitself and associating devices mounted thereon is relatively low, it ispossible to dispense with the permanent magnet means incorporated in thelateral frame 106 and 106, and it is also possible to dispense with thecentral magnet means and to support the vehicle merely by lateral magnetmeans.

When driving the magnet vehicle along the wall surface 129, the adhesionend portion 114 of the electromagnet 101 must be adjusted beforehandwith respect to its location. Thereafter, the magnet vehicle is broughtadjacent to the wall surface 129 of the structural member by the use ofappropriate means such as a crane, and then by applying electric currentto the electromagnet 101 and energizing the same the magnet vehicle canbe firmly supported on the wall surface 129. The entire operation of themagnet vehicle on the wall surface 129 is controlled by a suitablecontrol means.

By the driving of the driving wheels 104 and 104' by means of thedriving motors 126 and 126, the magnet vehicle is advanced straight.When it is required to alter the direction of travel, compressed air isintroduced into the air cylinder means 107 through the port 1 11 so thatthe electromagnet 101 fixed at one end of the rod 110 may be lowereddownward due to the pressure acted upon the piston 109, to the extentthat the adhesion end portion 114 abuts to the surface 129. When theelectromagnet is further depressed, the driving belts 125 and 125 are atlast lifted away from the wall surface 129. The large gear 121 mountedon the electromagnet 101 is arranged such that it can be verticallyslided along the teeth of the spur gear 120 with its teeth engaged withthose of the spur gear. In the above case, the weight of the magnetvehicle itself and associated devices mounted thereon is supported onlyby the adhesion force of the electromagnet 101. After this, the steeringmotor 116 is activated to a desired direction and the spur gear 120 isrotated intermediary of the bevel gear 1 l7 and 118 and shaft 119. Asthe large gear 121 of the electromagnet 101 cannot be rotated relativeto the wall surface 129 of the structural member owing to the fact thatthe vehicle is then being supported by the adhesion end portion 114 awayfrom the wall surface 129, the spur gear 120 is obliged to rotate aroundthe periphery of the large gear 121, whereby the magnet vehicle canalter the direction of its travel as desired. After the vehicle isaltered of its direction of travel to a desired direction, the rotationof the vehicle is stopped by switching off the steering motor 116, andat the same time compressed air is introduced into the air cylindermeans 107 through the port 112 and discharged from the port 111 so thatthe piston 109 is lifted upward to the extent that the adhesion endportion 114 of the electromagnet 101 is retracted relative to the undersurface of the driving belts 125 and 125'. Thereupon, said belts 125 and125' are brought into contact with the wall surface 129 again, and thusthe magnet vehicle is ready for advancing straight forward by the aid ofthe driving motors 126 and 126'.

In one embodiment of the magnet vehicle in accordance with the presentinvention, in which:

outernal dimension; width 850 mm X length 1050 mm X height 380 mmtraveling speed; 10 meters per minute,

electrical capacity of the center magnet; 1.2 KW DC capacity of drivingmotors; 1 KW X 2 capacity of reduction motor; 1 KW weight of the magnetvehicle; 370 kg gap between the heel pieces 18 and 18' of the lateralmagnet means 13 and 13 and the structural member 38; 3 mm gap betweenthe yoke 34 of the center magnet means 24 and the structural member 38;8 mm the adhesion force exerted has been proved to be 1680 kg, and thevehicle loaded with 50 kg could travel even on a vertical wall ofstructural member 38 at will. For the purpose of utilizing this magnetvehicle in painting operation for ships, there were installed on thedeck of a ship a control board, power source for direct electriccurrent, a pump and a compressor used for painting. Further, there wasmounted on the magnet vehicle a spray nozzle for painting. With thearrangement as above, the magnet vehicle was placed on a side wall of aship having a radius of curvature of 10 meters, and operated by theremote control means installed on the deck of the ship. It has provedfrom this experiment that the painting according to the magnet vehicleis satisfactory and the surface to be painted was not scarred or damagedat all.

In another embodiment of the magnet vehicle in accordance with thepresent invention, the arrangement was as follows,

electrical capacity of the center magnet; 0.4 KW

capacity of the driving motors; 0.75 KW X 2 capacity of the steeringmotor; 0.4 KW

load; kg

traveling speed; 15 meters per minute gap between the adhesion endportion and the wall surface; 5 mm The magnet vehicle arranged as abovewas driven along a circular pass of 8 meter radius and it has provedthat it takes three seconds to alter the direction of travel by Thevehicle could move over the wall surface at will without damaging thesame.

Although, in the aforementioned embodiments, flexible endless V-belts orflat belts have been used as driving means, it is of course possible touse such belt as coupled by chain or the like with elastic element ofsuch a reinforced plastic material. Similarly with respect to thecentral magnet means, it is possible to arrange such that a worm and aworm wheel are secured at one end of the shaft of the electromagnet, orotherwise piston and cylinder means are provided for moving theelectromagnet upward anddownward by the aid of air pressure or oilpressure. Similarly, in place of springs used for damping purpose in theguide pulley means, any device'having damping effect, for example, thosein use of air pressure or oil pressure can be employed. v

Although in the second embodiment the magnet vehicle was operated withthe gap between the adhesion end portion and the wall surface alwaysconstant, it is possible by adjusting the gap by use of a gap sensor toutilize efficiently the adhesion force according to the circumstances.

According to the magnet vehicle of the present invention, it is possibleto dispense with the platform and other devices which have beennecessary in case of conventional methods. Further, it is easy to removethe magnet-vehicle from the structural member since the vehicle isadhered thereto only by magnetic force, and in addition to this themagnet vehicle can be supported safely upon the structural surface evenin case that the electromagnet is not energized. Furthermore, inaccordance with the present invention, the magnet vehicle can alter itsdirection of travel with high reliability even on a considerablyrestricted operation surface, without damaging same at all, and it hasproved that the efficiency of painting operation can be increased byabout three times and the expense can be reduced to about one-tenth incomparison with the conventional arts.

Although the present invention has been described with respect tospecific details of certain embodiments thereof, it is not intended thatsuch details be limitations on the present invention except insofar asset less track means located on either side of said frame adapted to bein contact with the surface for frictional driving of the vehicle,lateral magnet means provided between the upper run and the lower run ofsaid end less track means, central magnet means disposed centrally ofsaid frame and assisting said lateral magnet means to keep the vehicleattracted on the surface by the magnetic force thereof, displacementmeans for displacing said central magnet means downwardly relative tosaid endless track means so that said magnetic vehicle can be supportedon said surface solely by said central magnet means, steering means forrotating the remainder of said magnet vehicle relative to said centralmagnet means when said magnet vehicle is supported solely by saidcentral magnetic means, and motor means for driving said endless trackmeans.

2. A magnet vehicle as defined in claim 1 characterized in that saidsteering means for rotating the remainder of said vehicle relative tothe central magnet means includes a ring gear fitted around the centralmagnet means and planetary gear means secured at one end of a shaft tobe meshed with said ring gear, said shaft being rotatably journalled ina portion of said frame, another gear means secured at the other end ofthe shaft, and a motor for driving said another gear means.

1. A magnet vehicle for operating on the surface of iron or steelbodies, comprising a frame, a pair of endless track means located oneither side of said frame adapted to be in contact with the surface forfrictional driving of the vehicle, lateral magnet means provided betweenthe upper run and the lower run of said endless track means, centralmagnet means disposed centrally of said frame and assisting said lateralmagnet means to keep the vehicle attracted on the surface by themagnetic force thereof, displacement means for displacing said centralmagnet Means downwardly relative to said endless track means so thatsaid magnetic vehicle can be supported on said surface solely by saidcentral magnet means, steering means for rotating the remainder of saidmagnet vehicle relative to said central magnet means when said magnetvehicle is supported solely by said central magnetic means, and motormeans for driving said endless track means.
 2. A magnet vehicle asdefined in claim 1 characterized in that said steering means forrotating the remainder of said vehicle relative to the central magnetmeans includes a ring gear fitted around the central magnet means andplanetary gear means secured at one end of a shaft to be meshed withsaid ring gear, said shaft being rotatably journalled in a portion ofsaid frame, another gear means secured at the other end of the shaft,and a motor for driving said another gear means.